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Biomedical subjects

M Topp

Publications and source records attributed to M Topp.

3 recordsLinked to original sources

Intrauterine growth and gestational age in preterm infants with cerebral palsy.

In a case-control study, gestational age and intrauterine growth of 191 preterm singleton infants 1971-82 with cerebral palsy were compared to all preterm live-born singletons in Denmark in 1982 (N = 2203). The distribution of gestational age among preterm cases was slightly bimodal with maximum values at 29 and 32 weeks. The risk for cerebral palsy was highest in the infants with gestational age 28-30 weeks (OR = 5.6 (4.0-7.8), 95% confidence interval). Birth weight deviation, in the 34-36 weeks infants, expressed as the number of standard deviations from the mean birth weight for gestational age, was more negative in cases than in controls (P < 0.001). The frequency of small for gestational age (SGA) was 13% in cases and 9% in controls (OR = 1.5 (0.96-2.3), 95% confidence interval). The odds for cerebral palsy being SGA, was lower in 28-30 weeks (OR = 0.22 (0.06-0.86), 95% confidence interval), the same in 31-33 weeks (OR = 0.83 (0.35-2.0), 95% confidence interval) and higher in 34-36 weeks (OR = 5.2 (2.9-9.5), 95% confidence interval). In conclusion, preterm infants with cerebral palsy are born earlier than other preterm infants. Small for gestational age is associated with cerebral palsy in preterm infants only above 33 weeks.

Case-Control Studies

IL-4 and TNF-alpha induce changes in integrin expression and adhesive properties and decrease the lung-colonizing potential of HT-29 colon carcinoma cells.

The colon carcinoma cell line HT-29 was used to explore the potential of interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-alpha) to modify integrin expression and adhesive functions of tumor cells in vitro and to examine corresponding metastatic effects in vivo. Preincubation of HT-29 cells with 100 U/ml of IL-4 for 48 h downregulated the surface expression of the integrin subunits alpha 2, alpha 3, beta 1 and beta 4 after 48 h, whereas the alpha 1 subunit was upregulated. In contrast, 100 U/ml to TNF-alpha selectively upmodulated the expression of alpha v. Attachment to fibronectin of cells treated with IL-4 increased twofold (63.5% vs 32.4%). Adhesion to fibronectin (54.0% vs 32.4%) and vitronectin (37.9% vs 16.4%) was elevated in the case of TNF-alpha stimulation. Using an experimental metastasis model, HT-29 cells showed a significant reduction of their lung-colonizing potential in nude mice when preincubated with IL-4 for 48 h before intravenous injection. The decrease also observed for TNF-alpha-treated cells was less pronounced. The data indicate that the cytokines IL-4 and TNF-alpha can act as direct regulators of adhesive mechanisms of tumor cells bearing adequate receptors, thus influencing lung-colony formation.

Animals

Oxidative phosphorylation diseases and cerebellar ataxia.

Oxidative phosphorylation (OXPHOS) diseases can be caused by mutations in nuclear genes or mitochondrial DNA (mtDNA) genes. mtDNA mutations include complex mtDNA rearrangements in which large segments of mtDNA are duplicated or deleted and point mutations in which single nucleotide substitutions occur within transfer RNA (tRNA) genes, ribosomal RNA (rRNA) genes, or mitochondrial genes encoding OXPHOS polypeptides. Although over 30 pathogenic mtDNA point mutations and over 60 different types of mtDNA deletions are known (Shoffner and Wallace, 1995; Wallace et al., 1994), only a subset of these mutations are associated with cerebellar ataxia. This review focuses on the clinical, biochemical, and genetic features of OXPHOS diseases caused by mtDNA mutations in which ataxia is a common manifestation.

Adult